Daniele Bonvicini1, Rafael Boscolo-Berto2,3, Alessandro De Cassai4, Michele Negrello4, Veronica Macchi5,6, Ivo Tiberio1, Annalisa Boscolo4, Raffaele De Caro5,6, Andrea Porzionato5,6. 1. Department of Urgency and Emergency, Anesthesiology and Intensive Care Unit, University-Hospital of Padova, Padua, Italy. 2. Department of Neurosciences, Institute of Human Anatomy, University of Padova, Via A. Gabelli 65, 35127, Padua, Italy. rafael.boscoloberto@unipd.it. 3. Veneto Region Reference Center for the Preservation and Use of Gifted Bodies, Veneto Region, Padua, Italy. rafael.boscoloberto@unipd.it. 4. Anesthesia and Intensive Care Unit, University-Hospital of Padova, Padua, Italy. 5. Department of Neurosciences, Institute of Human Anatomy, University of Padova, Via A. Gabelli 65, 35127, Padua, Italy. 6. Veneto Region Reference Center for the Preservation and Use of Gifted Bodies, Veneto Region, Padua, Italy.
Abstract
PURPOSE: Erector spinae plane (ESP) block is an interfascial blockade used in different clinical scenarios. This study investigated the ventral extent of dye diffusion in ESP block. METHODS: The ultrasound-guided ESP block was bilaterally performed with an injection at the T5 vertebral level (21-Gauge, 50 mm needle), using diluted black tissue marking dye (20 mL; 1:4 ratio with standard saline solution) instead of local anesthetic on two fresh-frozen corpses within the body donation program of the University of Padova. Subsequently, the gross anatomical dissection was performed by a combined posterior plus anterior approach, and the histotopographic examination completed. RESULTS: Macroscopically by gross anatomical dissection, the dye spreading ranged on the dorsal side of the chest from T2/3 to T10/11 with an extension up to 10 cm laterally, and on the ventral side of the chest from T2/3-T9/10. Microscopically by histotopographic examination, the dye diffused ventrally to the intercostal spaces (2-3 and 5-6 spaces on the right and left, respectively) by following the blood vessels coupled to the dorsal nerve passing through the costotransverse foramen. CONCLUSIONS: The anterior pathway of dye diffusion from the site of injection within the erector spinae muscle group during an ESP block seems to follow the blood vessels and dorsal rami of spinal nerves, suggesting the passing through the costotransverse foramen to reach the anterior paravertebral space and the intercostal nerves. These findings display an anterior histotopographic diffusion of dye resembling a paravertebral block.
PURPOSE: Erector spinae plane (ESP) block is an interfascial blockade used in different clinical scenarios. This study investigated the ventral extent of dye diffusion in ESP block. METHODS: The ultrasound-guided ESP block was bilaterally performed with an injection at the T5 vertebral level (21-Gauge, 50 mm needle), using diluted black tissue marking dye (20 mL; 1:4 ratio with standard saline solution) instead of local anesthetic on two fresh-frozen corpses within the body donation program of the University of Padova. Subsequently, the gross anatomical dissection was performed by a combined posterior plus anterior approach, and the histotopographic examination completed. RESULTS: Macroscopically by gross anatomical dissection, the dye spreading ranged on the dorsal side of the chest from T2/3 to T10/11 with an extension up to 10 cm laterally, and on the ventral side of the chest from T2/3-T9/10. Microscopically by histotopographic examination, the dye diffused ventrally to the intercostal spaces (2-3 and 5-6 spaces on the right and left, respectively) by following the blood vessels coupled to the dorsal nerve passing through the costotransverse foramen. CONCLUSIONS: The anterior pathway of dye diffusion from the site of injection within the erector spinae muscle group during an ESP block seems to follow the blood vessels and dorsal rami of spinal nerves, suggesting the passing through the costotransverse foramen to reach the anterior paravertebral space and the intercostal nerves. These findings display an anterior histotopographic diffusion of dye resembling a paravertebral block.